M-x list-directory (C-x C-d) is probably what you want?

or

M-x dired, then
M-x dired-hide-details-mode

If you always want to hide detail, add a hook. Like this:

    (defun xah-dired-mode-setup ()
      "to be run as hook for `dired-mode'."
      (dired-hide-details-mode 1))
    (add-hook 'dired-mode-hook 'xah-dired-mode-setup)

If you really want them all in a single line, M-x shell-command (M-!) and `ls -m` is probably the best.

Or, better I think is just M-x eshell, then do `ls`.